Odin was the chief god in the Norse mythology, and the father of
Thor, Balder, Hoder, Tyr, Bragi, Heimdall, Ull, Vidar, Hermod and Vali.
His wives were Fjorgyn, Frigga and Rind. He had a bad habit to roam around Midgard in human
disguise
seducing and impregnating women. This is why many mortals were able to trace
their ancestry back to him.

Thor

Thor was the son of Odin and Fjorgyn. He was the god of
thunder, the sky, fertility and the law. Armed with his strength-giving
items, a belt and the hammer Mjölnir, he had a simple way of
righting wrongs: he more or less killed everything that moved. The other gods
-mostly Loki- occasionally took advantage of Thor's simplicity.

Loki

Loki can be called the 'wizard of lies' and is in many ways the most
interesting god in Asgard. Loki was related to Odin, but their
relationship was rather strange. He came to Asgard either as of right or because
Odin and he entered into a blood-brotherhood.

Frey

Frey was a fertility god of the the Vanir race. He was the son of
Njord and came
to Asgard as a hostage along with his father and sister Freya.

Sif was the goddess who married Thor and bore his stepson (by
Odin), Ull. The vikings (and their gods) admired golden hair, and she was exceptionally proud of hers, so Loki cut it
all off while she was asleep.

Hel

Hel was a goddess (or a monster), a daughter of Loki and Angrboda,
who ruled over Niflheim, which was the land of the dead. There were
different opinions of whether she was alive or
dead. Ull, in his role as god of winter, was supposed to spend a few months each year as Hel's lover.
Hel and her
ghostly army were going to support the other gods at Ragnarok, after which her
domain would go out in flames.